The effects of (E)-2-hexenal on morphological, physiological, and biochemical indices of postharvest disease Penicillium cyclopium spores

The study investigated the effects of (E)-2-hexenal on morphology and function of Penicillium cyclopium spores, and these conidia were treated with (E)-2-hexenal at various concentrations. (E)-2-hexenal at 8x minimum fungicidal concentration (8x MFC, 2560 mu l/L) severely damaged conidia membranes through scanning electron microscopy, which resulted in the changes in membrane permeability parameters including the release of intracellular adenosine triphosphate content, loss of 260 nm-absorbing materials, and the decrease of extracellular pH, the increase in extracellular conductivity, and membrane leakage as determined by propidium iodide staining. (E)-2-hexenal (<= 2 x MFC, 640 mu l/L) always induced superoxide dismutase and catalase enzyme activities in P. cyclopium conidia. These results suggest that (E)-2-hexenal damages fungal spore membranes, and inhibit spore germination in a dose-dependent manner, causing a series of changes in membrane permeability parameters, which serves as the inhibitory mechanism of (E)-2-hexenal against P. cyclopium. Practical applications (E)-2-hexenal treatment significantly resulted in serious detrimental damages in the morphology and function in P. cyclopium spores. The work presented (E)-2-hexenal could control fungal pathogens through disruption of cell membrane integrity and membrane permeability. The results revealed that (E)-2-hexenal can be used as a new anti-fungal agent against P. cyclopium.